Cell Cycle Genes encode Cell Cycle Proteins, which control the cell division cycle. This family of proteins, classified on the basis of related function, includes a wide variety of classes, including cyclin-dependent kinases, mitogen-activated kinases, cyclins, and phosphoprotein phosphatases, as well as their putative substrates, such as chromatin-associated proteins, cytoskeletal proteins, and transcription factors. (NCI) [ ]